As a technique for transmitting data at optimum efficiency corresponding to a communication quality of a transmission path, a method of decreasing a bit rate when the communication quality of the transmission path is low and increasing a bit rate when the communication quality is high is used.
Specifically, this method is, for example, a method of applying, in packet communication, FEC (Forward Error Correction) to data of an object to be transmitted when a communication quality does not satisfy a predetermined standard to thereby substantially decrease a bit rate and not applying FEC when the communication quality satisfies this standard to thereby substantially increase a bit rate. Such a technical method is described in, for example, prior art document: Association of Radio Industries and Business “Digital Automobile Telephone System Standard RCR STD-27 J version”, May 30, 2002.
However, in the conventional technique, when FEC is applied to data, an arrangement of bits in a bit string constituting this data significantly changes. Therefore, a device on a side for receiving and restoring the data needs to know whether FEC is applied to the data. Therefore, it is necessary to separately transmit data indicating presence or absence of use of FEC in accordance with a complicated protocol that causes deterioration in transmission efficiency.
The invention has been devised in view of such a problem of the conventional technique and it is an object of the invention to provide a base band signal generating device, a base band signal generating method, and a program for processing data of a transmission object such that a reception side can restore the data without recognizing whether processing is applied to the data and for transmitting the data at proper efficiency corresponding to a communication quality.